Rotor construction for axial flow compressors



D. J. CLARKE 2,884,186.

ROTOR CONSTRUCTION 'FOR AXIAL 110w COMPRESSORS April 28, 1959 FiledApril 25. 1954 INVENTOR. W M

United States Patent ROTOR CONSTRUCTION FOR AXIAL FLOW- COMPRESSORSDaniel J. Clarke, Bay City, Mich. assignor to The Stalker Corporation, acorporation of Michigan Application April 23, 1954, Serial No. 425,132

6 Claims. (Cl. 239-134) This invention relates to axial flowcompressors.

An object of the invention is to provide an axial flow rotor of lightand economical construction. ,7

Another object is to provide a rotor for axial flow compressorscomprising sheet metal blades.

Other objects will appear from the description, drawings and claims.

The above objects are accomplished by the means illustrated in theaccompanying drawings in which- Fig. 1 is a fragmentary axial section ofa compressor incorporating a rotor according to this invention;

Fig. 1a is a fragmentary. axial section of an end disk and the adjacentring;

Fig. 2 is a fragmentary development of the outer surface of the rotor atthe root ends of the blades;

Fig. 3 is an axial front view of a rotor wheel;

Fig. 4 is a fragmentary section of the rotor near the blade roots takenon the line 44 of Fig. 2;

Fig. 5 is a fragmentary section on line 5-5 in Fig. 2;

Fig. 6 is a fragmentary axial section through the compressor; and

Fig. 7 is a section on line 77 in Fig. 6.

Referring to the drawings a fragment of a compressor is shown in Fig. 1.It comprises the rotor 2 mounted in the case means 4 for rotation aboutthe axis of shaft 6 borne in the bearing 8. When rotated the rotorinduces a flow of fluid through the inlet 9 and through the annular duct10 defined between the rotor 2 and'the case means 4. The rotor blades 12are of light hollow sheet metal construction and divide this duct 10into rotor flow passages between the rotor blades.

As shown particularly in Figs. 2-6, the rotor is comprised of a wheelfor each rotor stage which in turn is comprised'of rings like 13 and 14whose teeth 15 mesh to position one relative to the other and totransmit torque therebetween.

The rings are clamped between two end disks 16 and 17 by the tie rods23. These tie rods pass through aligned apertures in radially inwardlyextending flanges 13a and 14a respectively. The disk 17 is at the rearend of the series of rings forming the rotor.

The adjacent rings have notches 18 and 19 which register to define anopening 20 for receiving the roots of the blades which have enlargedportions 21 thereon as shown in Fig. 4. At the localities of the bladeroots the rings are thickened to provide for the sockets 22 which housethe blade roots.

The blades are mounted for oscillation about the center of the arcuatesurfaces 24. Their oscillation or vibration is damped by the damper wire26 which preferably passes through the bearing 28 in sliding relationthereto. The bearing is fixed to the stem 30 of the blade 12. See Figs.3, 4, 6 and 7 particularly. When the rotor is in operation centrifugalforce presses the wire outward and mag nifies the frictional efiectbetween the wire and the hearing 28. This damps the vibration of theblades.

The wire could also be fixed in the element 28. Then the out-of-phasevibration of the blades tends to damp one another.

The rotor structure disclosed is very light since the material ispositioned chiefly in the rim of the rotor, that is at the rings. Alsothe driving torque is applied sub stantially at the rim of the rotorwhere the driving forces can be a minimum.

If the blades are made hollow particularly of sheet metal construction,their weight is small so that the centrifugal loads at their roots aresmall. They can accordingly be supported by simple rings without hubdisks extending across their encircled space. The radial thickness ofthe rings can be and is preferably only a small fraction of the order of0.5 times the maximum radius of the ring.

The rings such as 13 and 14 can be recessed as at 32 and 34 to receivethe shroud rings 38 at the tips of the stator blades 42 and 44.

It will now be clear that the structure is light since the wheelmaterial is concentrated at the rotor rim where it is most effective indriving the blades; also that the structure is simple and economical toproduce by standard machine tools and the like.

While I have illustrated specific forms of the invention, it is to beunderstood that variations may be made therein and that I intend toclaim my invention broadly as indicated by the appended claims.

What is claimed is:

l. A rotor for an axial flow compressor adapted for operation in a casecomprising a plurality of bladed rotor wheels arranged in side by siderelation, each said wheel including a pair of rings of narrow radialwidth and peripherally spaced axial flow blades carried thereon, saidrings having a plurality of peripherally spaced notches therein todefine a series of blade openings, said blades having root portionsextending into said openings for guiding and supporting said blades inoperative relation upon said wheels, said openings having arcuatesurfaces engageable by said root portions of said blades providing forlimited oscillatory movement of each said blade in its said opening,said rings being formed with interfitting surfaces on adjacent facesproviding for transmission of torque from one wheel to anotherindependently of the support for said blades, a pair of end disksenclosing the outer faces of said wheels forming the support therefor,and shaft means for rotatably mounting said end disks.

2. A rotor for an axial flow compressor adapted for operation in a casecomprising a plurality of bladed rotor wheels arranged in side by siderelation, each said wheel including a pair of rings of narrow radialwidth and peripherally spaced axial flow blades carried thereon, saidrings having a plurality of peripherally spaced notches therein todefine a series of blade openings, said blades being hollow and havingroot portions extending into said openings for guiding and supportingsaid blades in operative relation upon said wheels, said openings havingarcuate surfaces engageable by said root portions of said bladesproviding for limited oscillatory movement of each said blade in itssaid opening, stems extending into said hollow blades and projectingradially inwardly of said rings, means engaging the radially innerportions of the series of said stems to damp the vibrations of saidblades, said rings being formed with interfitting surfaces on adjacentfaces providing for transmission of torque from one wheel to anotherindependently of the support for said blades, a pair of end disksenclosing the outer faces of said wheels forming a rotor assemblythereof, and shaft means for rotatably mounting said end disks.

3. In combination in an axial flow compressor for impelling a flow ofelastic fluid therethrough, a rotor mounted for rotation about an axis,said rotor comprising spaced end disks, shaft means for rotatablysupporting said end disks for rotation about said axis, a plurality ofbladed rotor wheels positioned in series between said end disks, eachsaid wheel comprising a ring of narrow axial. Width, means fixing saidrings to said end disks to receive a driving torque therefrom to rotatethem at high blade tip speeds to cause a substantial increase in densityand pressure of said fluid, some of said rings having teeth on the axialend thereof interfitting with the teeth of the next adjacent ring fortransmission of torque therebetween, each said ring of a pair of saidrings with interfitting teeth having a plurality of peripherally spacednotches registering one with another to define a plurality of bladeopenings, peripherally spaced hollow sheet metal axial flow bladescarried by said rings and extending outwardly through said openings, andmeans adjacent the circumference of said rings and disposed between apair of said rings which form a wheel and radially outwardly of saidaxis supporting said blades entirely from said rings and independentlyof said teeth.

4. In combination in an axial flow compressor for impelling a flow ofelastic fluid therethrough, a rotor mounted for rotation about an axis,said rotor comprising spaced end disks, and a plurality of bladed rotorwheels positioned in series between said end disks, each said wheelincluding a ring of narrow axial width, means fixing said rings to saidend disks to receive a driving torque therefrom for rotation at highblade tip speeds to cause a substantial increase in density and pressureof said fluid, some of said rings having teeth on the axial end thereofinterfitting with the teeth of the next adjacent ring for transmissionof torque therebetween, each said ring of a pair of said rings withinterfitting teeth having a plurality of peripherally spaced notchesregistering one with another to define a plurality of blade openingsperipherally spaced hollow sheet metal axial flow blades carried on saidrings and extending outwardly through said openings, said blades beingof light hollow sheet metal construction limiting the centrifugal loadson said rings during said rotation and adapting each said ring to havesaid narrow width less than about 5 percent of the maximum radius ofsaid rings, and means adjacent the circumference of said rings anddisposed between a pair of said rings which form a wheel and radiallyoutwardly of said axis supporting said blade entirely from said ringsand independently of said teeth.

5. In combination in an axial flow compressor for impelling a flow ofelastic fluid therethrough, a rotor mounted for rotation about an axis,said rotor comprising spaced end disks, and a plurality of bladed rotorwheels positioned in series between said end disks, each a} said wheelincluding a ring of narrow radial width, means fixing said rings to saiddisks to receive a driving torque therefrom, some of said rings havingclutch teeth on the axial end thereof interlitting with the teeth of thenext adjacent ring for transmission of torque therebetween, each saidring of a pair of said rings with interfitting teeth having a pluralityof peripherally spaced notches registering one with another to define aplurality of blade openings, peripherally spaced axial flow bladescarried in said blade openings, said blades having enlarged portions atthe roots thereof, and means forming sockets in said rings for receivingsaid blade enlargements therein.

6. In combination in an axial flow compressor for impelling a flow ofelastic fluid therethrough, a rotor mounted for rotation about an axis,said rotor comprising spaced end disks, and a plurality of bladed rotorwheels positioned in series between said end disks, each said wheelincluding a ringof narrow radial width, means fixing said rings to saiddisks to receive a driving torque therefrom, some of said rings havingclutch teeth on the axial end thereof interfitting with the teeth of thenext adjacent ring for transmission of torque therebetween, each saidring of a pair of said rings with interfitting teeth having a pluralityof peripherally spaced notches registering one with another to define aplurality of blade openings, peripherally spaced axial flow bladescarried in said blade openings, said blades having enlarged portions atthe roots thereof, said rings being thickened to provide sockets forreceiving said blade enlargements therein.

References Cited in the file of this patent UNITED STATES PATENTS1,601,402 Lorenzen Sept. 28, 1926 1,891,948 Rice Dec. 27, 1932 2,641,440Williams June 9, 1953 2,649,243 Stalker Aug. 18, 1953 2,655,307 Bucklandet a1. Oct. 13, 1953 2,675,174 McDowall Apr. 13, 1954 2,717,554 StalkerSept. 13, 1955 FOREIGN PATENTS 55,102 Netherland Aug. 16, 1943 138,839Australia Sept. 26, 1950 439,567 Germany Jan. 14, 1927 543,557 GreatBritain Mar. 3, 1942 853,988 Germany Oct. 30, 1952 872,816 Germany Apr.9, 1953 1,056,070 France Oct. 21, 1953 UNITED STATES PATENT OFFICECERTIFICATE OF CORRECTION Patent No 23,884,186 April 28, 1959 Daniel J,Glarke It is herebfi certified that error appears in the-printedspecification of the above numbered patent requiring correction and thatthe said Letters Patent should read as corrected below.

Column 2', line 14, for "O5 time's" read 0065 times column 3,,

lines 35 and Bo for "openings peripherally" read We openings,peripherally,

Signed and sealed this let day of September 1959 (SEAL) fittest:

KARL Em AXLINE Attesting Officer ROBERT C. WATSON Commissioner ofPatents

